1. Field of the Invention
The present invention relates to a vehicular travel control device.
2. Description of the Related Art
In the past, there is a known, for example, a following travel control device that stops and moves a subject vehicle according to changes in the travel state including the stopping and moving of a preceding vehicle (for example, see Japanese Patent No. 4230385).
When this kind of following travel control device performs a control for stopping the subject vehicle while following a preceding vehicle, the vehicle is stopped so that a predetermined initial target inter-vehicle distance is equal to the inter-vehicle distance between the preceding vehicle and the subject vehicle at the time of stopping. In addition, if an instruction is made in a stop state so as to decrease the inter-vehicle distance between the preceding vehicle and the subject vehicle at the time of stopping by the input operation from the driver, the inter-vehicle distance is decreased up to the predetermined shortest target distance at the time of stopping.
Meanwhile, in the following travel control device according to the related art, a predetermined inter-vehicle distance at the time of stopping is secured between the preceding vehicle and the subject vehicle, regardless of the gradient of the road being traveled of the preceding vehicle and the subject vehicle. For this reason, the inter-vehicle distance at the time of stopping may cause the driver to feel uneasy. That is, when a stopped preceding vehicle starts on an uphill road, there is a concern that the preceding vehicle may move backward. Further, when the subject vehicle is to be stopped on a downhill road, there is a concern that there is insufficient deceleration. For this reason, if the same inter-vehicle distance at the time of stopping as that in the case of a flat road is set in the case of an uphill road or downhill road, a driver of the subject vehicle is apt to feel that the inter-vehicle distance is excessively short at the time of stopping. As a result, there is a possibility in that the driver of the subject vehicle feels uneasy due to the following travel control.
The present invention was made to solve the problem and an object thereof is to provide a vehicular travel control device that can prevent a driver from feeling uneasy from following travel control.